In this paper, a novel model of a frequency reconfigurable microstrip patch antenna based on MEMS... more In this paper, a novel model of a frequency reconfigurable microstrip patch antenna based on MEMS (microelectromechanical system) technology is introduced. Fabrication process of the proposed antenna is comprised of bulk and surface micromachining. Patch of the antenna is deposited over a silicon platform. The platform is created by structuring the silicon membrane which is formed through bulk micromachining of a silicon chip. The patch and the platform beneath it are discretized to facilitate their vertical displacement over underside air gap. Thermal actuation is used as driving mechanism. Operational mechanism of the antenna is such that by downward relocation of the patch, its resonant frequency shifts downward. Thermal actuators are connected to the platform and applying voltage to them cause downward shift in resonant frequency of the antenna. FEM (finite element method) simulations confirm mechanical and microwave performances of the antenna which are investigated by theoretical analyses. From mechanical point of view, antenna has tolerable mechanical stability and microwave point of view indicates that return losses are good (below $-$ 10 dB) and radiation patterns are very close to each other with reasonable gains. Moreover VSWR is less than 2 throughout the frequency tuning range. In the proposed antenna by applying a CMOS compatible voltage in the range of 0–4.5 V to each thermal actuator, the resonant frequency of the antenna shifts from 17.37 GHz in up-sate position to 15.07 GHz in down-state position. As a result of this frequency shift, a frequency tuning range of 2.3 GHz with bandwidths of 3.9 % in up-state and 1.4 % in down-state positions is achieved.
This paper presents a novel micromachined wideband frequency tunable microstrip patch antenna. Th... more This paper presents a novel micromachined wideband frequency tunable microstrip patch antenna. The fabrication process of the proposed reconfigurable antenna system is composed of a process combination of bulk and surface micromachining. Thermal actuation is employed as the driving mechanism. The out-of-plane motion of the thermal actuators normal to the antenna surface deflects the patch downward respect to the fixed ground plane. This deflection decreases the air gap height beneath the patch and consequently, resonant frequency of the antenna. The up-state operating frequency of the antenna is 22.19GHz. A tuning range of 334MHz is achieved by the CMOS compatible actuation voltage of 2.65V. Simulations show a bandwidth of 1.26 and 1.17GHz for up and down-state (5μm deflection) positions, respectively. The microwave performance of the antenna and its mechanical behavior is investigated by finite-element analysis and good radiation pattern and return loss are obtained within the tuning range.
A new micromachined wideband frequency reconfigurable microstrip patch antenna is demonstrated in... more A new micromachined wideband frequency reconfigurable microstrip patch antenna is demonstrated in this paper. The tunable antenna system is fabricated by a combination of surface and bulk micromachining processes. Thermal actuation is employed to precisely adjust the operating frequency with voltage ranges compatible with today's CMOS circuitries. A bulk micromachined silicon membrane containing thermal actuators serves as a platform for antenna patch. The patch is excited by a 50Ω feed line through proximity coupling. The out-of-plane motion of the thermal actuators normal to the antenna surface deflects the patch downward respect to the fixed ground plane. This deflection reduces the air gap height between the antenna patch and feed line and consequently, resonant frequency of the antenna. The effect of initial air gap height on achievable tuning range and bandwidth of the antenna is also investigated and the optimum range is presented. The up-state operating frequency of the antenna is 22.61GHz which continuously can be lowered to 22.17GHz. A tuning range of 440MHz was achieved by a CMOS compatible actuation voltage of 1.5V. The bandwidth of the antenna for up and down-state positions are 1.34 and 1.27GHz respectively. The RF performance of the antenna and its mechanical behavior is investigated by FEM analysis and satisfactory results are obtained within the tuning range.
In this paper, a novel model of a frequency reconfigurable microstrip patch antenna based on MEMS... more In this paper, a novel model of a frequency reconfigurable microstrip patch antenna based on MEMS (microelectromechanical system) technology is introduced. Fabrication process of the proposed antenna is comprised of bulk and surface micromachining. Patch of the antenna is deposited over a silicon platform. The platform is created by structuring the silicon membrane which is formed through bulk micromachining of a silicon chip. The patch and the platform beneath it are discretized to facilitate their vertical displacement over underside air gap. Thermal actuation is used as driving mechanism. Operational mechanism of the antenna is such that by downward relocation of the patch, its resonant frequency shifts downward. Thermal actuators are connected to the platform and applying voltage to them cause downward shift in resonant frequency of the antenna. FEM (finite element method) simulations confirm mechanical and microwave performances of the antenna which are investigated by theoretical analyses. From mechanical point of view, antenna has tolerable mechanical stability and microwave point of view indicates that return losses are good (below $-$ 10 dB) and radiation patterns are very close to each other with reasonable gains. Moreover VSWR is less than 2 throughout the frequency tuning range. In the proposed antenna by applying a CMOS compatible voltage in the range of 0–4.5 V to each thermal actuator, the resonant frequency of the antenna shifts from 17.37 GHz in up-sate position to 15.07 GHz in down-state position. As a result of this frequency shift, a frequency tuning range of 2.3 GHz with bandwidths of 3.9 % in up-state and 1.4 % in down-state positions is achieved.
This paper presents a novel micromachined wideband frequency tunable microstrip patch antenna. Th... more This paper presents a novel micromachined wideband frequency tunable microstrip patch antenna. The fabrication process of the proposed reconfigurable antenna system is composed of a process combination of bulk and surface micromachining. Thermal actuation is employed as the driving mechanism. The out-of-plane motion of the thermal actuators normal to the antenna surface deflects the patch downward respect to the fixed ground plane. This deflection decreases the air gap height beneath the patch and consequently, resonant frequency of the antenna. The up-state operating frequency of the antenna is 22.19GHz. A tuning range of 334MHz is achieved by the CMOS compatible actuation voltage of 2.65V. Simulations show a bandwidth of 1.26 and 1.17GHz for up and down-state (5μm deflection) positions, respectively. The microwave performance of the antenna and its mechanical behavior is investigated by finite-element analysis and good radiation pattern and return loss are obtained within the tuning range.
A new micromachined wideband frequency reconfigurable microstrip patch antenna is demonstrated in... more A new micromachined wideband frequency reconfigurable microstrip patch antenna is demonstrated in this paper. The tunable antenna system is fabricated by a combination of surface and bulk micromachining processes. Thermal actuation is employed to precisely adjust the operating frequency with voltage ranges compatible with today's CMOS circuitries. A bulk micromachined silicon membrane containing thermal actuators serves as a platform for antenna patch. The patch is excited by a 50Ω feed line through proximity coupling. The out-of-plane motion of the thermal actuators normal to the antenna surface deflects the patch downward respect to the fixed ground plane. This deflection reduces the air gap height between the antenna patch and feed line and consequently, resonant frequency of the antenna. The effect of initial air gap height on achievable tuning range and bandwidth of the antenna is also investigated and the optimum range is presented. The up-state operating frequency of the antenna is 22.61GHz which continuously can be lowered to 22.17GHz. A tuning range of 440MHz was achieved by a CMOS compatible actuation voltage of 1.5V. The bandwidth of the antenna for up and down-state positions are 1.34 and 1.27GHz respectively. The RF performance of the antenna and its mechanical behavior is investigated by FEM analysis and satisfactory results are obtained within the tuning range.
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